Fig. 4
GABA promotes the recruitment of macrophages by CRC and induces M2 polarization through exosomes. A Immunofluorescence images showed that macrophages were relatively scarce in lung metastases of PBS group, while were abundant in GABA group. B The expression of CD206, CD163, Arginase1 and CD86 of THP1 cells upon administration of GABA were detected by Western blot and qRT-PCR. C. The expression of CD206, CD163, Arginase1 and CD86 of THP1 cells co-cultured with GABA-induced colon cancer cells or not by Western blot. D The expression of CD206, CD163, Arginase1 and CD86 of THP1 cells co-cultured with GABA-induced SW480 or not was detected by qRT-PCR. E, F Western blot and qRT-PCR showed that the expression of M2 makers (CD206, CD163, Arginase1) in THP1 cells was increased more significantly when added GABA-induced SW480-CM by qRT-PCR, while M1 maker was decreased. G Representative immunofluorescence image showed the internalization of PKH26-labeled LoVo-derived exosomes by THP-1 cells. H Western blot showed that the expression of M2 makers in THP1 cells was increased more significantly when added GABA-induced-SW480 derived exosomes, while M1 maker was decreased. I Immunofluorescence image showed that THP1 cells exhibited more pronounced M2 polarization when incubated GABA-induced SW480-derived exosomes for 3 days. J Western blot showed that GW4869(an inhibitor of exosome secretion) reversed the strengthened M2 polarization of THP1 cells upon incubated GABA-induced SW480-derived exosomes. SW480P: PBS-induced SW480 cells. SW480G:GABA-induced SW480 cells. LoVoP: PBS-induced LoVo. LoVoG:GABA-induced LoVo cells. Exo: Exosomes.CM: conditioned medium. All data were revealed as mean ± standard deviation (SD) for no less than three independent experiments. Significant P values showed as ***P < 0.001.**P < 0.01.*P < 0.05. ns means the difference was not significant